Take a bowl.Combine curd and bengal gram flour.Whisk well and keep aside.Heat ghee in a kadai.Add mustard seeds.When they crackle add other seasoning items.Stir for a few seconds.Add asafoetida powder.Add the curd and gram flour mixture.Add Turmeric powder Chilli powder Cumin powder and Coriander powderAllow to boil for sometime.Add potatoes and salt with one cup of water.Bring to a boil.Garnish with coriander leavesServe hot with chappati.